Anesthesia progress
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Recent adoption by the American Conference of Governmental Industrial Hygienists of a Threshold Limit Value of 50 ppm for an 8-hour average exposure to nitrous oxide (N2O) increases the likelihood for its regulation by state and federal occupational health agencies. This review outlines current information on the health risks of N2O inhalation to provide a basis from which safe and reasonably attainable exposure limits can be proposed. Although N2O was for many years believed to have no toxicity other than that associated with its anesthetic action, bone marrow depression in patients administered N2O for extended periods of time and neurological abnormalities in health care workers who inhaled N2O recreationally have disproved this notion. ⋯ Many, if not all, of the nonanesthetic-related adverse effects of N2O may be ascribed to this action. Animal and human studies indicate that the toxic effects of N2O are concentration- and time-dependent. It is suggested that a time-weighted average of 100 ppm for an 8-hour workday and/or a time-weighted average of 400 ppm per anesthetic administration would provide adequate protection of dental personnel and be achievable with existing pollution control methods.
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Anesthesia progress · Jan 1991
Flumazenil antagonizes the suppressive effect of midazolam on the somatosensory evoked potentials in the rat.
The effect of flumazenil, a specific benzodiazepine antagonist, on the midazolam-induced suppression of somatosensory evoked potentials (SEPs) following strong electrical stimulation of the upper lip was investigated in Wistar albino rats. The averaged SEPs were recorded from the contralateral surface of the skull in the temporal area. Each rat received midazolam in a dose of 10 mg/kg intraperitoneally. ⋯ The P1N1 amplitude recovered rapidly to the control value in the flumazenil group but not in the physiological saline group. No significant differences were found in the latencies of the P1 and N1 peaks before or after midazolam or flumazenil injection. It is suggested that flumazenil strongly antagonizes the midazolam-induced suppression of SEPs in the rat.
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Detection of expired carbon dioxide is one of the most reliable methods of avoiding accidental esophageal intubation. Although capnography has become a standard monitoring technique in the hospital operating room, it is rarely available in the office setting or other arenas where emergency endotracheal intubation may be required. ⋯ This semi-quantitative detector fits between the endotracheal tube and the breathing circuit and uses a pH-sensitive indicator that changes color in response to different concentrations of carbon dioxide. Clinical studies indicate that this device provides similar results to standard capnography, and its inclusion in the emergency kit is strongly recommended.